As well-known in the art, a humidifier is typically composed of a container body having a water tank installed therein for providing water to a humidifying or vaporizing chamber which produces and emits water vapor to the surrounding air.
A water supply tube in a humidifier connects a water tank to a vaporizing chamber, and is typically made of a metal pipe such as copper. However, such a metal pipe can be corrosive in the water when it is used for an extended period of time while forming harmful corrosive materials, germs, or toxic metallic oxides in the water tube, thus, causing the humidifier to produce harmful water vapor to the air.